The following United States patent applications, which were concurrently filed with this one on Oct. 28, 1999, are fully incorporated herein by reference: Method and System for Navigating a Catheter Probe in the Presence of Field-influencing Objects, by Michael Martinelli, Paul Kessman and Brad Jascob; Patient-shielding and Coil System, by Michael Martinelli, Paul Kessman and Brad Jascob; Coil Structures and Methods for Generating Magnetic Fields, by Brad Jascob, Paul Kessman and Michael Martinelli; Registration of Human Anatomy Integrated for Electromagnetic Localization, by Mark W. Hunter and Paul Kessman; System for Translation of Electromagnetic and Optical Localization Systems, by Mark W. Hunter and Paul Kessman; Surgical Communication and Power System, by Mark W. Hunter, Paul Kessman and Brad Jascob; and Surgical Sensor, by Mark W. Hunter, Sheri McCoid and Paul Kessman.
1. Field of the Invention
The present invention is directed generally to image guided surgery, and more particularly, to systems and methods for surgical navigation using one or more real-time ultrasound images overlaid onto pre-acquired images from other image modalities.
2. Description of the Related Art
Physicians have used pre-acquired ultrasound images to plan surgery for many years. Traditionally, ultrasound machines provide two-dimensional images of the relevant human anatomy. Physicians use such images to diagnose, among other things, fetal deformities. However, until recently, physicians have not used such ultrasound images that have been either pre-acquired or acquired in real time during surgery for surgical navigation purposes.
Some recent systems permit the use of ultrasound images in conjunction with a specialized software running on a computer to plan and execute a surgery. For example, among other systems, the Ultraguide system permits a physician to represent an icon representation of a surgical instrument on an ultrasound image. This system also plots a trajectory of a surgical instruments probe on a two-dimensional ultrasound image.
Similarly, the Life Imaging system also provides some help to a physician by converting two-dimensional ultrasound images into a three-dimensional cube. Subsequently, the physician may view an iconic representation of a surgical instrument on the cube.
However, none of these systems permit a physician to overlay images from other image modalities over ultrasound images along with a display of a surgical instrument on the overlaid images.
Objects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims.
One aspect of the present invention is directed to a surgical navigation system comprising several devices. In particular, the surgical navigation system includes an ultrasound machine, a computer coupled to the ultrasound machine, such that image data corresponding to the images acquired by the ultrasound machine can be transferred to the computer. In addition, the surgical navigation system includes a memory coupled to the computer which has computer instructions. The computer instructions when executed by the computer cause the computer to generate an icon representing the surgical instrument with a tip and the surgical instrument""s trajectory and to overlay the icon on a real-time ultrasound image, such that when the surgical instrument crosses the ultrasound image plane the form at of the surgical instrument""s trajectory is changed to represent the surgical instrument""s crossing of the ultrasound image""s plane. Furthermore, the surgical navigation system includes a localizer coupled to the ultrasound machine, which permits the system to localize the ultrasound probe, a part of the ultrasound machine. Finally, the surgical navigation system includes a display coupled to the computer for displaying the generated icon superimposed on the real-time ultrasound image acquired by the ultrasound machine.
The surgical navigation system further includes a display which can display a side view of the ultrasound image with a representation of the surgical instrument""s trajectory displaying the angle at which the surgical instrument""s trajectory intersects with the ultrasound image. In addition, the claimed system can calculate the angle at which the surgical instrument""s trajectory intersects with the ultrasound image. Moreover, the claimed system can also represent the angle at which the surgical instrument""s trajectory intersects with the ultrasound image using periodic markers.
Another surgical navigation system consistent with the present invention includes, an ultrasound machine and a video imaging device, such as a laparoscope where the ultrasound machine and the video-imaging device are coupled to the computer in a way that image data from both of these devices can be transferred to the computer. Alternatively, the video imaging device may also be an X-ray machine. In addition, the surgical navigation system has localizers attached to both the ultrasound machine and to the video imaging device. Furthermore, the system includes, a memory coupled to the computer, where the memory includes computer instructions. The computer instructions when executed by the computer cause the computer to overlay the video images acquired by the video imaging device onto the ultrasound image acquired by the ultrasound device such that the two images correspond to a common coordinate system. Finally, the system includes a display that can display the overlaid images.
In addition to the above mentioned systems, the concepts of the present invention may be practiced as a number of related methods.
One method consistent with the present invention is surgical navigation using images from other image modalities overlaid over ultrasound images. The method comprises calibrating the system, a step which need be performed initially only; registering image data-sets from other image modalities to patient anatomy, a physician scanning an area of interest using the ultrasound probe; the computer overlaying images from other image modalities onto the ultrasound images; the physician moving the ultrasound probe or other surgical instruments; and the system calculating a new location of the surgical instruments.
Another method consistent with the present invention is a method for calculating and displaying an ultrasound probe""s angle relative to an ultrasound image plane. The method comprises drawing a circle with its center at the point where the ultrasound probe""s trajectory crosses the ultrasound image plane. The circle""s radius represents the angle of the ultrasound probe relative to the ultrasound image plane. The angle of the ultrasound probe relative to the ultrasound image plane may also be displayed using periodic markers consistent with the present invention.
Still another method consistent with the present invention is a method to overlay image segmentations onto ultrasound images for surgical navigation. The method comprises extracting a two dimensional image from the three-dimensional image data-set; overlaying the extracted segmentation onto an ultrasound image corresponding to the same human anatomy; displaying the overlaid image along with an iconic representation of the surgical instruments; the physician moving the ultrasound probe or other surgical instruments; and the system calculating a new location of the surgical instruments.
An additional method consistent with the present invention is surgical navigation using three-dimensional image data-sets. The method comprises a physician acquiring a three-dimensional ultrasound image data-set; a computer reconstructing the image data-set into an orthogonal data-set; displaying the three-dimensional image on a display along with an iconic representation of the surgical instruments; the physician moving the ultrasound probe or other surgical instruments; and the system calculating a new location of the surgical instruments.
Yet another method consistent with the present invention is a method for detecting organ-matter shift from the time when CT or MR image data-sets are created to the time when the patient is operated upon. The method comprises correlating a real-time ultrasound image and a pre-acquired three-dimensional image to obtain a correlated two-dimensional image; selecting a first set of points on the real-time ultrasound image; selecting a corresponding second set of points on the correlated two-dimensional image; and displaying a vector representing the distance and the direction of the organ-matter shift.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate one (several) embodiment(s) of the invention and together with the description, serve to explain the principles of the invention.